Stopping cross sections forN4+→Hat low projectile velocity

Abstract

We study the time-dependent dynamics of N 4 + ions colliding with atomic hydrogen for projectile energies ranging from a fraction of an eV/amu up to 25 keV/amu using the electron-nuclear dynamics (END) formalism. The END theory obtains the electron-nuclear coupled equations of motion from the time-dependent variational principle employing a coherent state parametrization of the wave function. This approach leads to a simultaneous nonadiabatic dynamics of all the electrons and nuclei. We calculate and discuss dynamical trajectories, deflection functions, final charge states, differential cross sections, and energy loss. Quantum effects of the forward peak scattering are emphasized. Due to the strong interaction between the heavy and the hydrogen atom, a diffuse ion (vide infra) is formed, leading to acceleration or energy gain of the projectile. For the case of the electron transfer cross section, we found that it does not follow the Langevin-type cross section at low projectile energies as reported by other methods. Present results show good agreement with available experimental data.